1.14.15.18 (24R),25-dihydroxycholecalciferol + NADPH + O2 - 1.14.15.18 25-hydroxycholecalciferol + NADPH + O2 - 1.14.15.18 25-hydroxycholecalciferol + NADPH + O2 recombinant in E. coli 1.14.15.18 25-hydroxycholecalciferol + NADPH + O2 enzyme activity is correlated with phosphate content in serum 1.14.15.18 25-hydroxycholecalciferol + NADPH + O2 central role in calcium regulation 1.14.15.18 25-hydroxycholecalciferol + NADPH + O2 energy-dependent transhydrogenation is of importance 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 - 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 1,25(OH)2D3 is an antiproliferative agent that may inhibit proliferation of breast cancer cells 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 1,25-dihydroxyvitamin D3 (1,25-D3) is a key determinant of calcium homeostasis, cell proliferation and differentiation, calcium and vitamin D might have a protective function against colorectal tumor pathogenesis, overview 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 bioactivation 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 deficiency of the enzyme, due to mutation of residues Q65 and T409, in substrate binding causes vitamin D-dependent rickets type 1, overview 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 extra-renal functions of 1alpha-hydroxylase in vitamin D physiology, regulation, overview 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 regulation of enzyme expression in kidney proximal tubules, overview 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 substrate activation by the rate-limiting enzyme 1alpha-hydroxylase in cells of the immune system under control of immune stimuli, such as interferon-gamma, in pathological situations, such as sarcoidosis, this can lead to systemic excess of 1,25(OH)2D3 and hypercalcemia 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 the enzyme hydroxylates the major circulating form of vitamin D to the active systemic hormone 1,25(OH)2D3, local production of 1,25(OH)2D3 appears to occur also at other sites where 1alpha-hydroxylase is expressed for autocrine/paracrine regulation, overview 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 the enzyme is involved in the vitamin D signaling pathway in colonic epithelial cell differentiation by butyrate, mechanism, overview 1.14.15.18 25-hydroxyvitamin D + NADPH + O2 the enzyme is responsible for final hydroxylation of vitamin D3, in response to IFNgamma and CD14/TLR4 activation 1.14.15.18 25-hydroxyvitamin D2 + NADPH + H+ + O2 - 1.14.15.18 25-hydroxyvitamin D3 + H+ + O2 - 1.14.15.18 25-hydroxyvitamin D3 + NADPH + H+ + O2 - 1.14.15.18 25-hydroxyvitamin D3 + NADPH + O2 - 1.14.15.18 25-hydroxyvitamin D3 + NADPH + O2 final step of the activation of vitamin D 1.14.15.18 25-hydroxyvitamin D3 + NADPH + O2 final step of the activation of vitamin D, involved in tumor suppressing activity due to the tumor growth inhibiting effect of 1alpha,25-dihydroxyvitamin D3 1.14.15.18 cholecalciferol + NADPH + O2 - 1.14.15.18 additional information 25(OH)D3 therapy is useful for colorectal cancer chemoprevention but provitamin D is less likely to be useful for colorectal cancer chemotherapy, overview 1.14.15.18 additional information both butyrate and 1alpha-25(OH)2D3 stimulate differentiation of Caco-2 cells, while 25(OH)2D3 has no impact on cell differentiation 1.14.15.18 additional information colonic and renal vitamin D hydroxylases are regulated independently 1.14.15.18 additional information functional analysis of vitamin D metabolism in cancer, locally synthesized 1,25(OH)2D3 may be inefficient in preventing tumor progression, mechanism, overview 1.14.15.18 additional information immune regulation of the enzyme in monocytes, cross-talk between the JAK-STAT, the NFkappaB, and the p38 MAPK pathways is necessary, and direct binding of C/EBPbeta to its recognition sites in the promoter of the 1alpha-hydroxylase gene is a prerequisite, overview 1.14.15.18 additional information PTH and PTHrP are involved in enzyme regulation, PTH is the major protein hormone regulating calcium homeostasis, PTHrP is a PTH-like factor responsible for humoral hypercalcemia of malignancy, both peptides are required to achieve normal fetal skeletal morphogenesis, overview 1.14.15.18 additional information the enzyme is involved in local production of 1alpha,25-dihydroxyvitamin D, i.e. 1alpha,25(OH)2D3, in tumorigenesis 1.14.15.18 additional information the 1alpha-OHase gene is a tumor suppressor gene responsible for the normal regulation of prostate cell growth 1.14.15.18 additional information Vdh, a cytochrome P450 enzyme, is responsible for the biocatalytic conversion of vitamin D3, catalyzing the two-step hydroxylation of VD3, i.e. the conversion of VD3 to 25-hydroxyvitamin D3 (25(OH)VD3) and then of 25(OH)VD3 to 1alpha,25(OH)2VD3, a hormonal form of VD3. Anti-parallel substrate binding modes enable sequential hydroxylation, structure-function analysis, overview